Battery unit and electrical device

Abstract

A battery unit provided with a flat battery and a substrate having a circuit formed thereon is provided in a compact form as a whole. The battery unit ( 1 ) includes a flat battery ( 2 ) in a flat shape having an upper surface and a bottom surface and a substrate ( 61 ) fixed to one surface of the flat battery ( 2 ). A circuit component ( 62 ) is mounted on a surface of the substrate ( 61 ) on a side of the flat battery ( 2 ), and a positive electrode terminal ( 68 ) (charging terminal) electrically connected to a positive electrode side of the flat battery ( 2 ) and a negative electrode terminal ( 66 ) (GND terminal) electrically connected to a negative electrode side of the flat battery ( 2 ) are formed on a surface of the substrate ( 61 ) on the opposite side to the flat battery ( 2 ).

The invention claimed is: 
     
       1. A battery unit having a substantially circular cylinder shape, comprising:
 a flat battery in a flat shape having a first major flat surface and a second major flat surface, the flat battery having a substantially circular shape in a plan view; and 
 a substrate fixed to one of the first major flat surface and the second major flat surface of said flat battery to face said one of the first major flat surface and the second major flat surface of said flat battery, 
 a circuit component being mounted on a surface of said substrate facing to said flat battery, 
 a positive electrode terminal electrically connected to a positive electrode of the flat battery and a negative electrode terminal electrically connected to a negative electrode of the flat battery being formed on a surface of said substrate that is opposite to the surface facing to said flat battery. 
 
     
     
       2. The battery unit according to  claim 1 , wherein said flat battery has a cylindrical exterior can with a bottom and a sealing can adapted to cover an opening of the exterior can, and
 said substrate is fixed on said first major flat surface formed by said sealing can. 
 
     
     
       3. The battery unit according to  claim 2 , wherein said positive electrode terminal is electrically connected to one of said sealing can and an outer circumferential part of said exterior can fitted to the sealing can, and
 said negative electrode terminal is electrically connected to the other of said sealing can and the outer circumferential part of said exterior can to which said positive electrode terminal is not electrically connected. 
 
     
     
       4. The battery unit according to  claim 1 , wherein said substrate is fixed to said flat battery at such a distance to said flat battery that said circuit component is prevented from contacting the flat battery. 
     
     
       5. The battery unit according to  claim 4 , wherein a spacer adapted to provide said distance is provided between said substrate and said flat battery. 
     
     
       6. The battery unit according to  claim 1 , wherein said substrate has a shape and a size equal to an outer shape of the flat battery as said substrate is provided on said flat battery. 
     
     
       7. The battery unit according to  claim 1 , wherein a layered body including said flat battery and said substrate has at least a side surface covered with a resin material. 
     
     
       8. The battery unit according to  claim 7 , wherein outer circumferential parts of both end surfaces of said layered body are covered with said resin material. 
     
     
       9. An electrical device, comprising a case capable of storing the battery unit according to  claim 1 , wherein said case has a plurality of openings from which said positive and negative electrode terminals of said battery unit are exposed. 
     
     
       10. The battery unit according to  claim 2 , wherein an insulating gasket is provided between said exterior can and said sealing can, and said exterior can is bent inwardly and caulked to the sealing can.